This is an interesting accessory for your Glock 21 45 ACPhttp://www.mechtechsys.com/glock.php
Remove your slide and attach this upper and now you have a carbine that uses Glock magazines.
I have only used this a few times and it probably has about 100 rounds thru it. I shot it out to 25 yds and it was very accurate. A nice added benefit is, since 45 ACP is already subsonic all you hear when you shoot is a bit of a snap. Everyone who shoots this immediately gets a big grin. It is one of the most fun to shoot GUNS you will ever own. This package would cost close to $700 if you bought it New. If you don't want the red dot Bushnell I'll keep it and knock $30 off
No trades as I am selling to fund a new project